Thank you for your letter of September 25 requesting an Official Interpretation of Section 2B.21 of the Manual on Uniform Traffic Control Devices (MUTCD) regarding whether a U-turn is allowed from a lane over which a Left-Turn Only Mandatory Movement Lane Control (R3-5L) sign is placed or next to which a LEFT LANE MUST TURN LEFT (R3-7L) sign is placed. Your question is based upon the first sentence of Section 2B.21 of the 2003 MUTCD, which states:

If used, Mandatory Movement Lane Control (R3-5, R3-5a, and R3-7) signs (see Figure 2B-4) shall indicate only those vehicle movements that are required from each lane and shall be located where the regulation applies.

We have reviewed your request and have concluded that the use of an R3-5L and/or an R3-7L sign does not in and of itself prohibit a U-turn.

A few States prohibit U-turns at all intersections unless a particular approach is specifically signed that U-turns are allowed. In these States, it is the State law, not the presence of an R3 5L sign or an R3-7L sign that makes the U-turn illegal.

Most of the States allow U-turns at all intersections unless a particular approach is specifically signed that U-turns are prohibited. The prohibition of a U-turn from a mandatory left-turn lane in these States is accomplished by the installation of a No U-Turn (R3-4) sign. In these States, if the R3-4 sign is not present on an intersection approach on a two-way street or highway (or at a midblock median opening) that has a mandatory left-turn lane, then U-turns are also allowed from that lane.

Because of the differences in State laws, please be aware of any laws that exist in your State regarding U-turns.

Thank you for your interest in traffic operations and safety. For recordkeeping purposes, we have assigned the following official interpretation number and title: "2-670(I) - Meaning of Mandatory Left-Turn Sign with Respect to U-Turns." Please refer to this number and title in any future correspondence regarding this topic.

If you have further questions, please contact Mr. Fred Ranck at 708-283-3545 or Mr. Kevin Sylvester at 202-366-2161.